Photonic Properties of Dendrons and Dendrimers Incorporating Bis-(Diphenylphosphino)Diphenylpolyenes

1999 ◽  
Vol 598 ◽  
Author(s):  
L. Madrigal ◽  
K. Kuhl ◽  
C. Spangler
Keyword(s):  
Substituent Effects ◽  
Building Blocks ◽  
Optical Nonlinearity ◽  
Fine Tuning ◽  
Structure Property ◽  
Conjugated Molecules ◽  
Structure Property Relationships ◽  
Peak Broadening ◽  
Electro Optic ◽  
Device Applications

ABSTRACTSubstituent effects are quite important in fine tuning the photonic properties of conjugated molecules. In designing new chromophores, electron-donating or withdrawing substituents affect the electron distribution in the conjugation sequence, and previous studies to establish structure- property relationships have noted that when second row elements replace first row elements in the structure (e.g. S for O in donor groups), large enhancements of both the second and third order optical nonlinearity are observed. However, along with the observed enhancement of the nonlinearity, a red-shift in the absorption spectra occurs, often with peak broadening and tailing. This absorptivity-nonlinearity trade-off has been a constant concern in proposing organic materials for electro-optic device applications. In this presentation we will review our recent activity in designing new chromophores wherein P replaces N in donor groups and dendrimer building blocks, and the consequences and opportunities resulting from the observed large blue shifts in the spectra.

scholarly journals 1,3-Diketone Calix[4]arene Derivatives—A New Type of Versatile Ligands for Metal Complexes and Nanoparticles

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1214
Author(s):  
Sergey N. Podyachev ◽  
Rustem R. Zairov ◽  
Asiya R. Mustafina
Keyword(s):  
Structural Diversity ◽  
Building Blocks ◽  
Structural Features ◽  
Structure Property ◽  
One Pot ◽  
Arene Ligands ◽  
Structure Property Relationships ◽  
New Type ◽  
Synthetic Routes ◽  
Magnetic Resonance Imaging Mri

The present review is aimed at highlighting outlooks for cyclophanic 1,3-diketones as a new type of versatile ligands and building blocks of the nanomaterial for sensing and bioimaging. Thus, the main synthetic routes for achieving the structural diversity of cyclophanic 1,3-diketones are discussed. The structural diversity is demonstrated by variation of both cyclophanic backbones (calix[4]arene, calix[4]resorcinarene and thiacalix[4]arene) and embedding of different substituents onto lower or upper macrocyclic rims. The structural features of the cyclophanic 1,3-diketones are correlated with their ability to form lanthanide complexes exhibiting both lanthanide-centered luminescence and magnetic relaxivity parameters convenient for contrast effect in magnetic resonance imaging (MRI). The revealed structure–property relationships and the applicability of facile one-pot transformation of the complexes to hydrophilic nanoparticles demonstrates the advantages of 1,3-diketone calix[4]arene ligands and their complexes in developing of nanomaterials for sensing and bioimaging.

scholarly journals Capturing Waste Heat Energy with Charge-Transfer Organic Thermoelectrics

Synthesis ◽  
2018 ◽  
Vol 50 (19) ◽  
pp. 3833-3842 ◽  
Author(s):  
Vladimir Dimitrov ◽  
Simon Woodward
Keyword(s):  
Waste Heat ◽  
Electrical Power ◽  
Structure Property ◽  
Future Perspectives ◽  
New Materials ◽  
Organic Salts ◽  
Electrically Conducting ◽  
Structure Property Relationships ◽  
Device Applications ◽  
Key Aspects

Electrically conducting organic salts, known for over 60 years, have recently demonstrated new abilities to convert waste heat directly into electrical power via the thermoelectric effect. Multiple opportunities are emerging for new structure–property relationships and for new materials to be obtained through synthetic organic chemistry. This review highlights key aspects of this field, which is complementary to current efforts based on polymeric, nanostructured or inorganic thermoelectric materials and indicates opportunities whereby mainstream organic chemists can contribute.1 What Are Thermoelectrics? And Why Use Them?2 Current Organic and Hybrid Thermoelectrics3 Unique Materials from Tetrathiotetracenes4 Synthesis of Tetrathiotetracenes5 Materials and Device Applications6 Future Perspectives

Structure–property relationships in conjugated molecules

2001 ◽  
Vol 85 (2-3) ◽  
pp. 190-194 ◽  
Author(s):  
P.L. Burn ◽  
R. Beavington ◽  
M.J. Frampton ◽  
J.N.G. Pillow ◽  
M. Halim ◽  
...  
Keyword(s):  
Structure Property ◽  
Conjugated Molecules ◽  
Structure Property Relationships

scholarly journals Yellow electrochromic polymer materials with fine tuning electrofluorescences by adjusting steric hindrance of side chains

RSC Advances ◽  
2017 ◽  
Vol 7 (41) ◽  
pp. 25444-25449 ◽  
Author(s):  
Jian Liu ◽  
Yuchen Shi ◽  
Jingchuan Wu ◽  
Mei Li ◽  
Jianming Zheng ◽  
...  
Keyword(s):  
Steric Hindrance ◽  
External Potential ◽  
Polymer Materials ◽  
Fine Tuning ◽  
Side Chains ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Electrochromic Polymer

A series of novel conducting conjugated yellow-to-transmissive electrochromic (EC) polymers were designed to research their structure–property relationships, achieving electrofluorescent (EF) switching with applied external potential.

Synthesis and characterization of copolyimides containing fluorine and silicon surface-modifying agents

2017 ◽  
Vol 30 (3) ◽  
pp. 355-364
Author(s):  
John W Connell ◽  
Christopher J Wohl ◽  
Allison M Crow ◽  
William T Kim ◽  
Michelle H Shanahan ◽  
...  
Keyword(s):  
Laminar Flow ◽  
Surface Area ◽  
Surface Properties ◽  
Silicon Surface ◽  
Fuel Efficiency ◽  
Fine Tuning ◽  
Aromatic Diamine ◽  
Small Scale ◽  
Structure Property ◽  
Structure Property Relationships

Understanding the effects that monomer chemistries have on material properties allows for fine tuning of polymer synthesis for current and future applications. In order to develop polymeric-based coatings that have minimal surface adhesion characteristics when exposed to a variety of contaminants, a more thorough understanding of fundamental structure–property relationships is needed. In the aeronautics field, one concept to improve fuel efficiency of future aircraft is to modify the wing design to enable laminar flow. There is a concern that contaminants such as insect residue and other debris will adhere to airflow surfaces and have sufficient height to disrupt laminar flow thereby increasing drag with concomitant loss of fuel efficiency. One potential solution would be a polymer surface or coating that prevents or minimizes adhesion of such contaminants. As part of a structure–property relationship study involving modification of surface properties, a series of copolyimides containing both fluorine and silicon surface-modifying agents (SMAs) were prepared and characterized. Based on knowledge of structure–property relationships with polyimides containing either type of SMA, it was hypothesized that the combination of two different SMAs may lead to unique surface properties as the two SMAs competed for surface area at the polymer–air interface. Copolyimides for this study were prepared through a multistep synthesis using an aromatic dianhydride with equimolar amounts of diamino functionalities comprised of an aromatic diamine along with two SMAs. Films were cast from copoly(amide acid) solutions that were subsequently thermally imidized under a nitrogen atmosphere. Polyimide films and coatings were characterized using differential scanning calorimetry, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, contact angle goniometry, scanning electron microscopy, and energy-dispersive X-ray spectroscopy to determine chemical, thermal, and surface properties. Select samples were subject to high velocity insect impacts in a small-scale wind tunnel and the resulting residues were characterized for height and surface area and compared to those of a control surface.

When Current Does Not Follow Bonds: Current Density in Saturated Molecules

2019 ◽  
Author(s):  
Anders Jensen ◽  
Marc Hamilton Garner ◽  
Gemma C. Solomon
Keyword(s):  
Spatial Distribution ◽  
Current Density ◽  
Current Flow ◽  
Structure Property ◽  
Conjugated Molecules ◽  
Structure Property Relationships ◽  
Electron Transport Properties ◽  
Current Flows ◽  
Molecular Conductance ◽  
Insight Into

<div> <div> <div> <p>The tools commonly used to understand structure-property relationships in molecular conductance, inter-atomic currents and conductance eigenchannels, generally give us a sense of familiarity, with the chemical bonding framework and molecular orbitals reflected in the current. Here we show that while this picture is true for conjugated molecules, it breaks down in saturated systems. We investigate the current density in saturated chains of alkanes, silanes and germanes and show that the current density does not follow the bonds, but rather the nuclei define the diameter of a pipe through which the current flows. We discuss how this picture of current density can be used to understand details about the electron transport properties of these molecules. Understanding the spatial distribution of current through molecules, rather than simply the magnitude, provides a powerful tool for chemical insight into physical properties of molecules that are related to current flow. </p> </div> </div> </div>

An Overview of Conjugated Polymers in their Insulating Forms

1992 ◽  
Vol 247 ◽  
Author(s):  
Daniel J. Sandman
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Conjugated Polymers ◽  
Single Crystals ◽  
Optical Spectroscopy ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Device Applications ◽  
Linear Optical Properties ◽  
Linear Optical

ABSTRACTA brief overview is presented of the electrical and linear optical properties of conjugated polymers in their electrically insulating forms. Topics discussed include electronic structure and optical spectroscopy, thermochromism, and device applications, particularly electroluminescence. Structure-property relationships are stressed. Particular emphasis is placed on the properties of polydiacetylenes as they are available as macroscopic single crystals and, hence, are the best defined class of conjugated polymers.

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